Search PubMed⌕ Search

Biomedical subjects

B Jasani

Publications and source records attributed to B Jasani.

At least 73 records · Page 4Linked to original sources
PubMed1996

In vivo photoinduction of metallothionein in human skin by ultraviolet irradiation.

The aims of this study were to confirm and substantiate the in vivo cutaneous induction of metallothionein (MT) in human skin by UVR, which we have reported in brief previously, and to make a preliminary attempt to characterize the time course of this phenomenon. Buttock skin in 32 volunteers was irradiated with 2 MED of UVB and biopsies were taken at 24 h from matched non-irradiated and irradiated sites. In the kinetic study, skin biopsies from six volunteers were taken at 0, 2, 8, 24, and 48 h after 2 MED UVB irradiation. MT was immunolocalized in formalin-fixed, paraffin-embedded tissue with the monoclonal antibody E9 by an indirect immunoperoxidase method. Statistically significant differences between immunocytochemical scores were identified between non-irradiated (NI) and irradiated (I) skin within suprabasal keratinocytes (mean: NI = 1.2, I = 5.1; P = 0.01), superficial dermal fibroblasts (mean: NI = 2, I = 43; P < 0.001), mid-dermal fibroblasts (mean: NI = 0, I = 27; P < 0.001), and deep dermal fibroblasts (mean: NI = 0, I = 11; P < 0.001). In the kinetic study, no consistent rise in MT score with time was observed for the epidermal component. In dermal fibroblasts, however, the first statistically significant rise in immunocytochemically detectable MT was detected at 2 h and this was found to plateau beyond 8 h. These results confirm that ambient levels of UV irradiation are capable of inducing MT in human skin in vivo. Taken together with the relative rapidity of the response, this suggests a physiological photoprotective role for MT in human skin cells. The lack of a kinetic increase in epidermal MT may be due to high basal levels. Induction of MT in dermal fibroblasts may reflect the effects of a diffusible factor released from keratinocytes after UVR.

Buttocks↗
PubMed1996

Epidermal growth factor receptor status in hyperparathyroidism: immunocytochemical and In situ hybridization study.

The epidermal growth factor receptor (EGFr) family has been increasingly recognized as an important component in the control of normal cell proliferation and the pathogenesis of cancer. We have studied EGFr expression in 104 cases of hyperparathyroidism by immunocytochemistry (ICC) and by in situ hybridization (ISH). Using two different monoclonal antibodies, ICC for EGFr was performed on 66 cryostat sections and 38 wax-embedded parathyroid glands. ISH was performed on 49 of these glands using a cocktail of three anti-sense probes to EGFr mRNA and a nonspecific control probe to human HPV-18 virus. Breast and prostate tumors were employed as positive controls for both ICC and ISH. Controls demonstrated positive EGFr staining. None of the 104 parathyroid glands showed any ICC positivity. ISH displayed positive staining for EGFr mRNA in five of six carcinomas and eight of nine nonrenal hyperplastic glands. Only 3 of 15 adenomas and 3 of 19 renal hyperplastic glands showed positive staining. This difference was statistically significant between adenoma and carcinoma (p < 0.05) and between adenoma and nonrenal hyperplasia (p < 0.01) (Tukey's multiple comparison test). This study demonstrates that EGFr mRNA is present in parathyroid tumors. Expression in carcinoma and nonrenal hyperplasia is significantly different from adenoma and renal hyperplastic glands. In contrast, ICC failed to demonstrate EGFr protein expression. These findings suggest that either receptor numbers are too low to detect by ICC or there is a failure of mRNA translation. More studies are needed to establish whether the EGFr plays a role in the development of parathyroid cancer or hyperplasia.

Adenoma↗
PubMed1996

A malignant astrocytoma in a patient with AIDS: a possible association between astrocytomas and HIV infection.

We describe a malignant astrocytoma in a patient with AIDS confirmed at autopsy. The object of this report is to draw attention to a further example of an unusual tumour associated with HIV infection. This is the tenth case in the world literature and it is possible that this tumour is represented with a higher than expected frequency in this group of the population. This case and others add malignant astrocytoma to the differential diagnosis of an intracranial space occupying lesion in an AIDS patient.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Thrombomodulin as a marker of vascular and lymphatic tumours.

The aim of this study was to evaluate the utility of a new commercially available antibody to thrombomodulin as an endothelial marker in formalin-fixed paraffin-embedded tissue. The expression of thrombomodulin in a variety of 50 vascular and lymphatic neoplasms and malformations was compared to the expression of von Willebrand factor, QBend 10 (CD34) and JC70 (CD31). We showed that thrombomodulin was the best marker of lymphatic endothelium and also stained a higher percentage of malignant vasoformative tumours when compared to the other markers. We recommend the assessment of thrombomodulin expression in the differential diagnosis of malignant vasoformative neoplasms and in the detection of lymphatic endothelium for evidence of tumour permeation.

Biomarkers, Tumor↗
PubMed1996

High temperature antigen retrieval and loss of nuclear morphology: a comparison of microwave and autoclave techniques.

The use of high temperature antigen retrieval methods has been of major importance in increasing the diagnostic utility of immunocytochemistry. However, these techniques are not without their problems and in this report attention is drawn to a loss of nuclear morphological detail, including mitotic figures, following microwave antigen retrieval. This was not seen with an equivalent autoclave technique. This phenomenon was quantified using image analysis in a group of B cell lymphomas stained with the antibody L26. Loss of nuclear morphological detail may lead to difficulty in identifying cells accurately, which is important in the diagnostic setting-for example, when trying to distinguish a malignant lymphoid infiltrate within a mixed cell population. In such cases it would clearly be wise to consider the use of alternative high temperature retrieval methods and accept their slightly lower staining enhancement capability compared with the microwave technique.

Antigens, CD20↗
PubMed1996

Simian virus 40 large T antigen (SV40LTAg) primer specific DNA amplification in human pleural mesothelioma tissue.

BACKGROUND: DNA sequences and immunoreactivity associated with Simian virus 40 transforming factors, large T and small t antigens (SV40LTAg), suggestive of an aetiopathogenetic link have been identified in fresh frozen tissue of a high proportion of recent cases of pleural mesotheliomas from the United States, Italy and Germany. SV40 is not normally infective in man though it can transform human cells in tissue culture. A large cohort of people in the western world was accidentally parenterally inoculated with live SV40 through contaminated polio vaccines given between 1959 and 1961, and this might be a factor in the current continuing rise in the incidence of mesothelioma in the United States, Britain and Europe. The present study investigated the presence of SV40LTAg DNA in recently diagnosed cases of mesothelioma in Britain and the feasibility of detecting the SV40 DNA in archival tissue for retrospective analysis of cases in the peri-vaccination period. METHODS: DNA was extracted from fresh frozen and/or rehydrated formalin fixed, paraffin embedded tissue sections from nine recently diagnosed cases of mesothelioma, nine cases of pulmonary adenocarcinoma, and three reactive pleurae, and amplified by the polymerase chain reaction (PCR) using the primer pairs used previously on fresh frozen tissues-namely, the SV primer set directed at the LTAg gene sequence unique to SV40 and the PYV primer set directed at a sequence shared by SV40 and papovavirus strains BK and JC, respectively. RESULTS: PCR positivity with the SV primer set was restricted to four of the nine cases of mesothelioma. In contrast, six of the nine mesotheliomas, two of the nine adenocarcinomas, and one of the three reactive pleurae showed positivity with the PYV primers. The fresh frozen and corresponding formalin fixed, paraffin embedded tissue results concorded well with each other. CONCLUSIONS: Our data provide evidence for the association of SV40LTAg primer specific DNA with human pulmonary mesothelioma in the British population.

Adult↗
PubMed1996

Immunocytochemically detectable metallothionein is expressed by astrocytes in the ischaemic human brain.

The metallothioneins in vitro are both effective free radical and transitional metal ion scavengers. For this reason we investigated the expression of this protein in the normal CNS and after ischaemia using a monoclonal anti-metallothionein antibody to metallothionein isoforms I and II. Using immunohistochemistry and confocal laser scanning microscopy, we found anti-GFAP and anti-metallothionein were co-localized in astrocytes at the edges of infarcts. Energy dispersive X-ray microanalysis demonstrated high levels of copper and iron in the metallothionein positive reactive astrocytes. On the basis of the in vitro properties of these proteins, the functional importance of metallothionein in reactive astrocytes could be as a free radical scavenger and metal ion chelator.

Aged↗
PubMed1995

Wet autoclave pretreatment for immunohistochemical demonstration of oestrogen receptors in routinely processed breast carcinoma tissue.

The immunohistochemical demonstration of oestrogen receptor (OR) was performed on 32 randomly selected and routinely processed breast carcinomas after wet autoclave pretreatment of sections. The autoclave method was compared to the OR status found on frozen sections as well as to alternative pretreatment methods such as enzymatic predigestion and microwave irradiation. Using four different monoclonal antibody clones (H222, LH1, CC4-5, 1D5.26), the OR status was evaluated for each of the various pretreatment methods applied. All cases with a high OR content on frozen sections (n = 11) also showed a high OR status on wet autoclave-pretreated paraffin tissues using antibody clones 1D5.26 and CC4-5; in cases with low OR content on frozen sections, no false-negative cases were recorded using only the antibody 1D5.26 neither after wet autoclave nor microwave pretreatment. In addition, with this antibody, OR was detectable after autoclave pretreatment in two cases which were considered to be OR-negative even on frozen sections. When the primary antibody was omitted, no false-positive cases were observed after wet autoclave pretreatment. Thus, in our hands, wet autoclave pretreatment, in combination with the antibody 1D5.26, offers a highly sensitive method for the immunohistochemical demonstration of OR in routinely formalin-fixed, paraffin-embedded sections of breast carcinomas.

Antibodies, Monoclonal↗
PubMed1995

Metallothionein expression in duct carcinoma in situ of the breast.

In a previous study immunocytochemically detectable metallothionein (MT) expression in tumor cells of invasive duct carcinoma of the breast was shown to be associated with a more aggressive behavior and these findings have been subsequently confirmed by others. The aim of this study was to examine the prevalence and significance of MT positivity in preinvasive duct carcinoma in situ (DCIS). Fifty-five specimens of pure screen-detected DCIS were stained immunocytochemically for MT using the antibody E9. The intensity and distribution of MT staining were assessed using a semiquantitative method resulting in intensity distribution (ID) scores allowing duct by duct analysis in relation to architectural and cytological features of the DCIS. In general, myoepithelial cells around benign and malignant structures stained uniformly strongly for MT. Staining in DCIS was analyzed by architecture irrespective of cytology and by nuclear grade irrespective of architecture. The results showed that MT staining was significantly greater in comedo (ducts with necrosis) DCIS (ID = 97) compared with noncomedo (ducts without necrosis) DCIS (ID = 56) (P = .05 by Mann Whitney U statistic) and that low cytological grade (ID = 50) was associated with less MT staining than was high cytological grade (ID = 92) (P = .05 by Mann Whitney U statistic). These observations thus are consistent with the previously observed association between MT positivity and more aggressive behavior in invasive duct carcinoma of the breast.

Aged↗
PubMed1995

Alpha-actinin in nemaline bodies in congenital nemaline myopathy: immunological confirmation by light and electron microscopy.

To elucidate the protein composition of the nemaline bodies present in the muscle fibres of patients with congenital nemaline myopathy (CNM), we studied muscle biopsies with monoclonal antibodies against alpha-actinin and desmin in combination with a modified Gomori trichrome method. Electron microscopy of immunolabelled resin embedded sections was used for cytochemical localisation of alpha-actinin and desmin. Light microscopy of sections immunolabelled for alpha-actinin showed a cross-striation of the muscle fibres corresponding to the Z band pattern, focal thickening of the Z bands and additional reactivity with a granular pattern corresponding to the presence of nemaline bodies. Labelling of desmin did not show a similar pattern. Electron microscopy confirmed the presence of alpha-actinin in the nemaline bodies and Z bands, whereas desmin was only found in intermediate filaments around the Z bands. Western blots showed single, sharp alpha-actinin bands indistinguishable from normal. Our results provide direct evidence for the presence of alpha-actinin in nemaline bodies and a lack of quantitative or qualitative differences between the alpha-actinin of normal and CNM muscle.

Actinin↗
PubMed1995

Metallothionein expression in human breast cancer.

Metallothioneins are ubiquitous low molecular weight proteins characterised by high cysteine content and affinity for binding heavy metals. Abnormal metallothionein function and expression have been implicated in various disease states, including neoplasia. The aim of this study was to investigate metallothionein expression in human breast carcinoma. Sections of routinely fixed and processed blocks of tumour from 100 consecutive cases of primary operable breast carcinoma were stained for metallothionein using a recently developed monoclonal antibody and a standard immunohistochemical technique. Expression was scored on the basis of microscopical assessment of percentage of tumour cells staining. One patient was lost to follow-up and excluded from the study. A significant association (P < 0.0001) was observed between metallothionein expression and tumour type, with low levels being observed in tumours of good prognostic type. There was also a significant association with local recurrence (P < 0.02) and a significant difference (P < 0.02) in both survival and disease-free interval between tumours showing low and high levels of expression, the latter indicating a poor prognosis. No relationship was observed with patient age, tumour size, lymph node stage, histological grade, vascular invasion, menopausal status or oestrogen receptor status. The assessment of metallothionein expression in human breast cancer appears to provide prognostic information and may have important implications for understanding its development.

Breast Neoplasms↗
PubMed1995

Immunohistochemically detectable bcl-2 expression in colorectal carcinoma: correlation with tumour stage and patient survival.

The bcl-2 gene encodes for a mitochondrial membrane proto-oncoprotein, the expression of which is known to suppress programmed cell death (apoptosis). In the present study the prognostic value of bcl-2 proto-oncoprotein was immunohistochemically investigated in a series of 104 colorectal carcinomas. The bcl-2 staining patterns were semiquantitatively assessed and correlated with the pTNM stage, Dukes' classification, lymphocytic infiltration (Jass classification) and tumour grade as well as parameters not associated with prognosis (gender, age, tumour site, histological tumour type). Statistical analysis was carried out using the Kaplan-Meier method, the log-rank test, hazard ratios and their confidence intervals. Fifty-five out of 104 cases completely lacked immunohistochemical bcl-2 expression. Fewer than 5% of bcl-2-positive cells were found in 25, 5-50% in 17 and more than 50% in five cases. The extent of bcl-2 expression by tumour cells decreased significantly with respect to increasing tumour size (P < 0.05), decreasing lymphocytic infiltration (P < 0.05) and chance of poor clinical outcome (P < 0.05), but not with worsening of Dukes stages. In multivariate analysis (Cox regression model) bcl-2 expression remained as an independent prognostic parameter with Dukes' classification as stratification factor (P < 0.001). Although the biological functions of bcl-2 protein are not yet well understood, our results provide further evidence that bcl-2 oncoprotein appears to be associated with favourable clinical outcome. Thus immunohistochemical bcl-2 phenotyping of colorectal carcinoma may contribute in future to the clinical management of these patients.

Adult↗
PubMed1995

A comparative immunohistochemical study of malignant mesothelioma and renal cell carcinoma: the diagnostic utility of Leu-M1, Ber EP4, Tamm-Horsfall protein and thrombomodulin.

Metastatic renal cell carcinoma has occasionally been reported to mimic malignant pleural mesothelioma. Morphologically, histochemically and immunohistochemically, similarities in the two tumours exist making their differentiation difficult, particularly in biopsy specimens. The aim of this study was to make a comparative immunohistochemical analysis of the two tumours by use of a panel of four antibodies (Leu M1; Ber EP4; thrombomodulin and Tamm-Horsfall protein). Their suitability in differentiating between the two tumours was assessed. We examined 20 cases of renal cell carcinoma and 20 cases of malignant pleural mesothelioma. On immunostaining with Leu M1, 14 of 20 renal cell carcinomas were positive, yielding 70% sensitivity and 95% specificity and one of 20 mesothelioma. In comparison, Ber EP4 antibody stained only seven of 20 of the renal cell carcinomas. In addition, it was noted that four tubulo-papillary pattern renal cell carcinomas stained positively with both anti-Leu M1 antibody and Ber EP4 antibody. Thrombomodulin immunostaining was present in 11 of 20 mesotheliomas (55% sensitivity and demonstrated 95% specificity) and one of 20 renal cell carcinomas. For epithelial mesotheliomas only, thrombomodulin staining was identified in 10 of 14 cases. In the differentiation of renal cell carcinoma from epithelial mesothelioma we recommend the use of Leu M1 and thrombomodulin as diagnostically useful markers. None of the antibodies used in this study was effective in distinguishing sarcomatoid renal cell carcinoma from sarcomatous mesothelioma. Tamm-Horsfall protein showed little diagnostic utility in differentiating the two tumours.

Antibodies, Monoclonal↗
PubMed1995

Calcitonin and calcitonin gene-related peptide mRNA detection in a population of hyperplastic parathyroid cells also expressing chromogranin B.

BACKGROUND: In contrast to chromogranin A, chromogranin B is found only in small amounts in parathyroid tissue. We have recently shown that hyperplastic parathyroid glands occasionally show a pronounced focal chromogranin B expression. The aim of the present study was to further investigate the properties of these chromogranin B-positive cells by means of immunohistochemistry and in situ hybridization. EXPERIMENTAL DESIGN: Routinely processed tissues from 22 normal, 86 hyperplastic, and 36 neoplastic parathyroid glands were immunohistochemically investigated with Ab against parathyroid hormone (PTH), chromogranin A and B, calcitonin, and calcitonin gene-related peptide (CGRP). Additionally, six hyperplastic glands with focal chromogranin immunoreactivity as well as chromogranin B-negative normal, hyperplastic, and neoplastic (two cases each) glands were used for in situ hybridization studies for the demonstration of calcitonin and CGRP mRNA. RESULTS: All normal, hyperplastic, and neoplastic parathyroids were immunohistochemically PTH- and chromogranin A-positive. Twelve of 86 hyperplastic glands showed a focal chromogranin B immunoreactivity; in 10 out of these 12 cases, calcitonin could be colocalized with chromogranin B, chromogranin A, and PTH. CGRP was found in a fraction of calcitonin-positive cells in four cases. In hyperplastic glands, calcitonin mRNA was detected in areas with immunohistochemical calcitonin and chromogranin B positivity. CGRP mRNA was demonstrated only in a few cells. CONCLUSIONS: The results from this study demonstrate that calcitonin and CGRP may be synthesized and stored in PTH-producing hyperplastic parathyroid cells. The calcitonin-positive cells also strongly express chromogranin B, which is immunohistochemically not detectable in normal parathyroid cells. The functional significance of these findings remains to be elucidated.

Base Sequence↗
PubMed1994

The immunocytochemical demonstration of a relative lack of nerve fibres in the atrioventricular node and bundle of His in the sudden infant death syndrome (SIDS).

Whilst examining the variation with age of the nerve fibre content of the cardiac conduction system (CCS), using an immunocytochemical approach, it became evident that in two sudden infant death syndrome (SIDS) cases there was a selective lack of S100 positive nerve fibres in the atrioventricular (AV) node and His bundle. In the present study therefore, the examination of CCS with S100 was extended to a further five SIDS cases and three cases of sudden explained death. Also, in addition to S100--which selectively marks Schwann cells associated with both myelinated and non-myelinated nerves--PGP 9.5 (protein gene product) was used to reveal the presence of nerve axonal elements associated with the CCS. The results showed a uniform presence of S100 and PGP 9.5 positive nerve fibres in the sinoatrial (SA) node, the AV node and His bundle tissue of all three control cases. In contrast, five out of seven SIDS cases showed a uniform lack of staining with these markers in the AV node and His bundle tissue, whilst in the two remaining cases it was present in greatly diminished amounts. Staining in the SA node, although present in all seven cases, was reduced when compared with the control cases. This is the first time the CCS of SIDS cases has been studied with immunocytochemical markers of nerve elements. The overall results taken in conjunction with the epidemiology of SIDS suggest that the lack of AV node and His bundle innervation most probably reflects a delay in the development or maturation of the nerve elements of the CCS, similar to that noted for other parts of the central and peripheral nervous systems in SIDS.

Atrioventricular Node↗
PubMed1994

Wet autoclave pretreatment for antigen retrieval in diagnostic immunohistochemistry.

Interest has recently been shown in adapting the microwave oven heating technique for antigen retrieval to routine diagnostic immunocytochemical practice. Although it has proved effective as a specialist method for individual antigen localization in many laboratories, it has certain drawbacks which have hampered its wider routine application. These include the need to monitor the sections during the microwave treatment to prevent damage or drying, the limited number of sections that can be accommodated in the microwave oven, and the inevitable alteration in nuclear morphology induced by the microwaves. In order to obviate these difficulties, we have modified the wet autoclave method of Shin et al. (Lab Invest 1991; 64: 693-702) as a routine technique for retrieval of a variety of cell surface, cytoplasmic, and nuclear antigens in formalin-fixed and paraffin-embedded tissue. The technique produces even enhancement of several refractory antigens in anatomically different sites and has the potential to handle reliably up to 200 sections at a time without significant damage to the section or to nuclear morphology.

Antigens↗